The invention relates to methods for quenching electrophiles.
The transmission of viral diseases (e.g., hepatitis A, B, and C infections, acquired immunodeficiency syndrome, and cytomegalovirus infection) by blood or blood products is a significant problem in medicine. Other biological compositions, such as mammalian and hybridoma cell lines, products of cell lines, milk, colostrum, and sperm, can also contain infectious viruses. Screening donor biological compositions for viral markers can help reduce the transmission of viruses to recipients, but many screening methods are directed to only a few discrete viruses, and are therefore incomplete, and may also be less than 100% sensitive. It is therefore important to inactivate viruses contained in donor blood, blood products, or other biological compositions.
A number of agents that are capable of inactivating viruses in blood have been developed. For example, ethyleneimine monomer and ethyleneimine oligomers are very effective viral inactivating agents. Methods for producing and using ethyleneimine oligomers for inactivating viruses in biological compositions are generally described in U.S. Ser. No. 08/835,446 (filed Apr. 8, 1997), 08/521,245 (filed Aug. 29, 1995), 08/855,378 (filed May 13, 1997), 09/005,606 (filed Jan. 12, 1998), and 09/005,719 (filed Jan. 12, 1998), which are hereby incorporated by reference. Ethyleneimine oligomers are themselves chemically active, and must therefore be rendered non-reactive before a product, such as blood, is used clinically. Typically, a viral inactivating compound, such as ethyleneimine dimer, is added to a biological composition to inactivate infectious viruses that might be present in the composition. A quenching agent is then added to inactivate the ethyleneimine dimer that remains after viral inactivation has taken place. The end result is a biological composition that is relatively free of infectious viruses, but that is contaminated with quenched inactivating agent and with quenching agent.